Lanmuchang
Guizhou, Qianxinan Prefecture, Xingren County, China
Other hydrothermalTl (Hg, As)
- Type
- Low-temperature lorandite-bearing thallium deposit with mercury and arsenic in sedimentary rocks
World-class thallium deposit, one of the few where thallium forms its own minerals: dominant lorandite (TlAsS2) with other Tl minerals, realgar, orpiment, cinnabar and pyrite, over about 1.5 km²; late Permian mineralisation linked to biogenic enrichment, reworked by hydrothermal fluids in the Middle Triassic (Zhang et al., 2007, cited by Lu et al., 2026; Mindat). Mined from the 1990s to 2000 for Tl minerals only; poisoning and alopecia among residents in the 1960s and 1970s. Beyond the mining zone, weathered and dispersed lorandite supplies 45 to 95 % of soil Tl (three end-member model, Lu et al., 2026). Coordinates after Mindat; Lu et al. (2026) place the site in Huilong Town, Qiannan Prefecture, Mindat in Xingren County, Qianxinan Prefecture.
ε205Tl in ε units (parts per 10,000) Values of the same system
Standard : NIST SRM 997
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −1.65 ε | lorandite (TlAsS2), mixing end-member Value of Liu et al. (2024) used by Lu et al. (2026) as the lorandite end-member; uncertainty and number of analyses not given; the 136 mg/kg Tl attached to the end-member is incompatible with pure lorandite (about 59 % Tl) and probably refers to a lorandite-rich material. | Lu et al. (2026), Thallium isotopic compositions reveal a significant contribution of tha… |
Deposits of the same type
Cite this page
IsoFind Atlas (2026). Lanmuchang, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/lanmuchang/ (accessed 2026-10-16).
@misc{isofind2026lanmuchangisotopesignatures,
title = {Lanmuchang, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/lanmuchang/},
note = {Accessed 2026-10-16}
}Updated : 2026-10-16